The refrigerators with forced air circulation are usually provided with an air supply duct disposed on the rear wall of the refrigerating compartment and provided with air outlet front openings, which are turned to the spaces defined between the shelves of the refrigerating compartment.
A known usual construction of a refrigerator with forced air circulation is illustrated in FIGS. 1–2 of the enclosed drawings. In this construction, the refrigerator is of the combined type, comprising a freezing compartment 10 and a refrigerating compartment 20, which are superposed, provided with respective front doors 11 and 21, and separated by an intermediate wall 30.
Inside the refrigerating compartment 20 there are provided shelves 22 generally in a single piece and made of plastic or glass, between which is supplied the refrigerated air coming from front openings 23a provided in a diffusing duct 23, which is generally affixed internally to the central region of the rear wall of the refrigerating compartment and has an end, for example the upper end, receiving a refrigerated forced airflow coming from an air cooling compartment 40 lodging an evaporator 45 and a fan 46 and which, in the combined refrigerators, is usually disposed close to the rear region of the freezing compartment 10.
It should be understood herein that the diffusing duct 23 may be provided in the refrigerating compartment 20 of a simple refrigerator (not combined) in which the air cooling compartment 40 is positioned close to the rear upper region of the refrigerating compartment 20. Regardless of the fact of the refrigerator being combined, the return of the circulated air to the air cooling compartment is made by collecting said circulated air in the front or rear region of the refrigerating compartment 20.
With the prior art construction described above, the refrigerated air coming from the air cooling compartment 40 is supplied to the diffusing duct 23 of the refrigerating compartment 20, and then supplied to the latter through front openings 23a of the diffusing duct 23. The refrigerated air is thus supplied to the gaps or spaces V between the shelves 22, according to substantially horizontal paths extended in the central region of the refrigerating compartment 20 toward the front door 21, where said refrigerated air is converted in an ascending vertical flow developing between the door 21 and the front edge of the shelves 22 and which is collected, for example in the front upper region of the refrigerating compartment 20 and conducted to the air cooling compartment 40 by one or more return ducts 50 provided inside the intermediate wall 30 or in any other adequate part of the structure of the refrigerator, as illustrated by the arrows S.
The prior art forced air circulation system described above presents the disadvantage of producing a not completely uniform distribution of the refrigerated air to the different regions of the refrigerating compartment 20, due to the fact that the supply of refrigerated air is effected only in the central region of said compartment and from the rear wall thereof.
Another negative aspect of the known solutions results from the poor refrigeration to which the internal region of the front door 21 is submitted, since in this region is formed the ascending flow of the warmer circulated air that is returned to the air cooling compartment 40.
Another disadvantage of the known arrangements is due to the fact that the distribution of the refrigerated air inside the refrigerating compartment is fixed, allowing no alterations in the distribution of the refrigerated air to the different regions to be refrigerated.